int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
{
int err;
u32 addr = imr->imr_multiaddr.s_addr;
struct ip_mc_socklist *iml, *i;
struct in_device *in_dev;
int count = 0;
if (!MULTICAST(addr))
return -EINVAL;
rtnl_shlock();
if (!imr->imr_ifindex)
in_dev = ip_mc_find_dev(imr);
else {
in_dev = inetdev_by_index(imr->imr_ifindex);
if (in_dev)
__in_dev_put(in_dev);
}
if (!in_dev) {
iml = NULL;
err = -ENODEV;
goto done;
}
iml = (struct ip_mc_socklist *)sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
err = -EADDRINUSE;
for (i=sk->protinfo.af_inet.mc_list; i; i=i->next) {
if (memcmp(&i->multi, imr, sizeof(*imr)) == 0) {
/* New style additions are reference counted */
if (imr->imr_address.s_addr == 0) {
i->count++;
err = 0;
}
goto done;
}
count++;
}
err = -ENOBUFS;
if (iml == NULL || count >= sysctl_igmp_max_memberships)
goto done;
memcpy(&iml->multi, imr, sizeof(*imr));
iml->next = sk->protinfo.af_inet.mc_list;
iml->count = 1;
sk->protinfo.af_inet.mc_list = iml;
ip_mc_inc_group(in_dev, addr);
iml = NULL;
err = 0;
done:
rtnl_shunlock();
if (iml)
sock_kfree_s(sk, iml, sizeof(*iml));
return err;
}
void rtnl_lock(void)
{
rtnl_shlock();
}
